WP adding trailing "#!" to links?

I’m desperately trying to figure this out. I know it has something to do with the theme and its AJAX use. (or so at least I think!)

I’m adding a custom link to menus, but everytime it’s clicked WP adds the #!… For example mydomain.com/#!/example

I just want it to ignore adding that #! for this link/url. Is there anyway to bypass this? I’ve done some searching and can’t find a solution.

To test it yourself: https://mediabear.ca/decoy/ and please click the “Forums” link.